Alloy



Patented Sept. 5, E939 LHLGQT ALLOY Franz it. Home! and Earl I. Larsen,'lndianapolis,

Inch, assignors to P. R. Mallory & 00., Inc., Indianapolis, Ind., a corporation of Delaware No Drawing. Application March 9, 1939, Serial No: 260,745

3 Claims.

This inventionrelates to alloys, and more particularly copper alloys of improved characteris= tics.

The object of the invention is to produce an improved copper base alloy.

Another object is to produce a copper-magnesium alloy of comparatively low magnesium content, which can be hardened by means of the addition of a small percentage of silver, to a higher degree than has heretofore been possible.

Another object is to produce a copper alloy which has an excellent combination of hardness, electrical conductivity, resistance to annealin and resistance to scaling. r Specific objects are the provision of improved copper-silver-magnesium. alloys, especially suitable for fabrication into current carrying members, electrical contactors, welding eletrodes, current carrying bearings, soldering irons, retainer rings, pole shaders, collector rings, small gears,

switch blades, circuit breaker parts, internal combustion engine parts, turbine blades, parts which have to withstand oxidation and in general, parts which have to combine high thermal conductivity i with high strength.

Other objects of the invention will be apparent from the following description, taken in connection with the appended claims.

The present invention comprises a combination of elements, methods of manufacture and the product thereof, brought out and exemplified inthe disclosure hereinafter set forth, the scope of the invention being indicated in the appended claims.

While a preferred embodiment of the invention is described herein, it is contemplated that considerable variation may be made inthe method of procedure and the combination of elements, without departing from the spirit of the invention.

According to the preferred method of carrying out the present invention, an alloy is made containing copper, silver and magnesium, in the following proportions:

Per cent Silver .05 to 15 Magnesium .05 to 3 Copper Substantially the balance It is likewise possible to improve the characteristics of other copper-magnesium alloys, containing small percentages of additionalingrediients, by the addition of silver. Thus, coppermagnesium alloys, containing small proportions of beryllium, calcium; zinc, cadmium, indium, boron, aluminum, silicon, titanium, zirconium,

.tin, lead, thorium, uranium, lithium, phosphorus, vanadium, arsenic,.selen'ium, tellurium, manga- (nese, iron, cobalt, nickel, and chromium, can be improved by the addition of silver, in substantially the proportions indicated above.

A number of preferred compositions are given below:

' The above compositions are given by way of example only and we have found that a large number of variations can be made, producing desirable results within the composition range specifled. 85 In carrying out the present invention, a coppermagnesium alloy may first be made according to the conventional alloy making procedure of the prior art, and then the silver may be added. After the alloy has been prepared according to such alloying methods as described above, also a heat treatment may be applied to the alloys, consisting either in a quenching and subsequent aging operation, with or without intermediate working, or in a quenching operation only, or in an aging operation only. The quenching operations may be carried out at temperatures above 500 degrees C. and the drawing operations at temperatures.

below 500,

Both magnesium and silver have a solid solubility in copper, which decreases with temperature and therefore the alloys of the present 1nticularly as far as thermal and electrical conductivity are concerned.

Copper-magnesium-silver alloys provide new materials which'will' retain their properties even at elevated temperatures. 1

If these materials are being used for contactor contacts, they will show a longer life than materials of the prior art andmore particularly copper, and they can be operated under more severe electrical loads, without causing fusing and stick-- ing. At the same time, the contactresistance will remain low. 's

While the present. invention as to its objects and advantages has been described herein, as carried out in specific embodiments thereof, it is not desired to be limited thereby, but it is intended to cover the inv'ention broadly, within the spiri and scope or the appended claims.

What is claimed is: 1. An alloy containing about .05 to 3% magnesium, .05 to 15% silver and the remainder cop- 2. An alloy containing about .5 to 2% magnesium, ;05 to 2% silver and the remainder copper.

3. An alloy containing about .1 to 2% magnesium, 1 to 6% silver and the remainder copper.

EARL I. LABBEN. 

